Improved importing

DataLayer/Migrations/20191125182309_Fresh.Designer.cs

@@ -9,7 +9,7 @@ using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
 namespace DataLayer.Migrations
 {
     [DbContext(typeof(LibationContext))]
-    [Migration("20191119144803_Fresh")]
+    [Migration("20191125182309_Fresh")]
     partial class Fresh
     {
         protected override void BuildTargetModel(ModelBuilder modelBuilder)
@@ -129,6 +129,13 @@ namespace DataLayer.Migrations
                     b.HasIndex("Name");
 
                     b.ToTable("Contributors");
+
+                    b.HasData(
+                        new
+                        {
+                            ContributorId = -1,
+                            Name = ""
+                        });
                 });
 
             modelBuilder.Entity("DataLayer.LibraryBook", b =>

DataLayer/Migrations/20191125182309_Fresh.cs

@@ -200,6 +200,11 @@ namespace DataLayer.Migrations
                 columns: new[] { "CategoryId", "AudibleCategoryId", "Name", "ParentCategoryCategoryId" },
                 values: new object[] { -1, "", "", null });
 
+            migrationBuilder.InsertData(
+                table: "Contributors",
+                columns: new[] { "ContributorId", "AudibleContributorId", "Name" },
+                values: new object[] { -1, null, "" });
+
             migrationBuilder.CreateIndex(
                 name: "IX_BookContributor_BookId",
                 table: "BookContributor",

DataLayer/Migrations/LibationContextModelSnapshot.cs

@@ -127,6 +127,13 @@ namespace DataLayer.Migrations
                     b.HasIndex("Name");
 
                     b.ToTable("Contributors");
+
+                    b.HasData(
+                        new
+                        {
+                            ContributorId = -1,
+                            Name = ""
+                        });
                 });
 
             modelBuilder.Entity("DataLayer.LibraryBook", b =>

DataLayer/UNTESTED/EfClasses/Book.cs

@@ -62,7 +62,8 @@ namespace DataLayer
             string description,
             int lengthInMinutes,
 			IEnumerable<Contributor> authors,
-			IEnumerable<Contributor> narrators)
+			IEnumerable<Contributor> narrators,
+			Category category)
         {
             // validate
             ArgumentValidator.EnsureNotNull(audibleProductId, nameof(audibleProductId));
@@ -80,8 +81,7 @@ namespace DataLayer
             _seriesLink = new HashSet<SeriesBook>();
             _supplements = new HashSet<Supplement>();
 
-            // since category/id is never null, nullity means it hasn't been loaded
+			Category = category;
-            CategoryId = Category.GetEmpty().CategoryId;
 
             // simple assigns
             Title = title;
@@ -233,8 +233,8 @@ namespace DataLayer
 
         public void UpdateCategory(Category category, DbContext context = null)
         {
-            // since category is never null, nullity means it hasn't been loaded
+            // since category is never null, nullity means it hasn't been loaded. non null means we're correctly loaded. just overwrite
-            if (Category != null || CategoryId == Category.GetEmpty().CategoryId)
+            if (Category != null)
             {
                 Category = category;
                 return;

DataLayer/UNTESTED/EfClasses/Category.cs

@@ -18,8 +18,7 @@ namespace DataLayer
     public class Category
     {
         // Empty is a special case. use private ctor w/o validation
-        public static Category GetEmpty() => new Category { CategoryId = -1, AudibleCategoryId = "", Name = "", ParentCategory = null };
+        public static Category GetEmpty() => new Category { CategoryId = -1, AudibleCategoryId = "", Name = "" };
-        public bool IsEmpty() => string.IsNullOrWhiteSpace(AudibleCategoryId) || string.IsNullOrWhiteSpace(Name) || ParentCategory == null;
 
         internal int CategoryId { get; private set; }
         public string AudibleCategoryId { get; private set; }

DataLayer/UNTESTED/EfClasses/Contributor.cs

@@ -6,6 +6,9 @@ namespace DataLayer
 {
     public class Contributor
 	{
+		// Empty is a special case. use private ctor w/o validation
+		public static Contributor GetEmpty() => new Contributor { ContributorId = -1, Name = "" };
+
 		// contributors search links are just name with url-encoding. space can be + or %20
 		//   author search link:   /search?searchAuthor=Robert+Bevan
 		//   narrator search link: /search?searchNarrator=Robert+Bevan

DataLayer/UNTESTED/LibationContext.cs

@@ -60,6 +60,9 @@ namespace DataLayer
 			modelBuilder
 				.Entity<Category>()
 				.HasData(Category.GetEmpty());
+			modelBuilder
+				.Entity<Contributor>()
+				.HasData(Contributor.GetEmpty());
 
             // views are now supported via "query types" (instead of "entity types"): https://docs.microsoft.com/en-us/ef/core/modeling/query-types
         }

DtoImporterService/BookImporter.cs

@@ -63,28 +63,39 @@ namespace DtoImporterService
 
 		private static Book createNewBook(Item item, LibationContext context)
 		{
+			// absence of authors is very rare, but possible
+			if (!item.Authors?.Any() ?? true)
+				item.Authors = new[] { new Person { Name = "", Asin = null } };
+
 			// nested logic is required so order of names is retained. else, contributors may appear in the order they were inserted into the db
 			var authors = item
 				.Authors
 				.Select(a => context.Contributors.Local.Single(c => a.Name == c.Name))
 				.ToList();
 
+			var narrators
+				= item.Narrators is null || !item.Narrators.Any()
 				// if no narrators listed, author is the narrator
-			if (item.Narrators is null || !item.Narrators.Any())
+				? authors
-				item.Narrators = item.Authors;
 				// nested logic is required so order of names is retained. else, contributors may appear in the order they were inserted into the db
-			var narrators = item
+				: item
 					.Narrators
 					.Select(n => context.Contributors.Local.Single(c => n.Name == c.Name))
 					.ToList();
 
+			// categories are laid out for a breadcrumb. category is 1st, subcategory is 2nd
+			// absence of categories is very rare, but possible
+			var lastCategory = item.Categories.LastOrDefault()?.CategoryId ?? "";
+			var category = context.Categories.Local.SingleOrDefault(c => c.AudibleCategoryId == lastCategory);
+
 			var book = context.Books.Add(new Book(
 				new AudibleProductId(item.ProductId),
 				item.Title,
 				item.Description,
 				item.LengthInMinutes,
 				authors,
-				narrators)
+				narrators,
+				category)
 			).Entity;
 
 			var publisherName = item.Publisher;
@@ -94,11 +105,6 @@ namespace DtoImporterService
 				book.ReplacePublisher(publisher);
 			}
 
-			// categories are laid out for a breadcrumb. category is 1st, subcategory is 2nd
-			var category = context.Categories.Local.SingleOrDefault(c => c.AudibleCategoryId == item.Categories.LastOrDefault().CategoryId);
-			if (category != null)
-				book.UpdateCategory(category, context);
-
 			book.UpdateBookDetails(item.IsAbridged, item.DatePublished);
 
 			if (!string.IsNullOrWhiteSpace(item.SupplementUrl))

DtoImporterService/CategoryImporter.cs

@@ -33,8 +33,11 @@ namespace DtoImporterService
 				.Except(localIds)
 				.ToList();
 
+			// load existing => local
+			// remember to include default/empty/missing
+			var emptyName = Contributor.GetEmpty().Name;
 			if (remainingCategoryIds.Any())
-				context.Categories.Where(c => remainingCategoryIds.Contains(c.AudibleCategoryId)).ToList();
+				context.Categories.Where(c => remainingCategoryIds.Contains(c.AudibleCategoryId) || c.Name == emptyName).ToList();
 		}
 
 		// only use after loading contributors => local

DtoImporterService/ContributorImporter.cs

@@ -47,11 +47,10 @@ namespace DtoImporterService
 				.ToList();
 
 			// load existing => local
+			// remember to include default/empty/missing
+			var emptyName = Contributor.GetEmpty().Name;
 			if (remainingContribNames.Any())
-				context.Contributors.Where(c => remainingContribNames.Contains(c.Name)).ToList();
+				context.Contributors.Where(c => remainingContribNames.Contains(c.Name) || c.Name == emptyName).ToList();
-			// _________________________________^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-			// i tried to extract this pattern, but this part prohibits doing so
-			// wouldn't work anyway for Books.GetBooks()
 		}
 
 		// only use after loading contributors => local

InternalUtilities/UNTESTED/AudibleApiValidators.cs

@@ -29,12 +29,12 @@ namespace InternalUtilities
 		{
 			var exceptions = new List<Exception>();
 
+			// a book having no authors is rare but allowed
+
 			if (items.Any(i => string.IsNullOrWhiteSpace(i.ProductId)))
 				exceptions.Add(new ArgumentException($"Collection contains item(s) with blank {nameof(Item.ProductId)}", nameof(items)));
 			if (items.Any(i => string.IsNullOrWhiteSpace(i.Title)))
 				exceptions.Add(new ArgumentException($"Collection contains item(s) with blank {nameof(Item.Title)}", nameof(items)));
-			if (items.Any(i => i.Authors is null))
-				exceptions.Add(new ArgumentException($"Collection contains item(s) with null {nameof(Item.Authors)}", nameof(items)));
 
 			return exceptions;
 		}